The quote below, and the article it comes from, is clearly not about 'cycling'. For that I'm not even sure the research has really been done. To the extent that pilots and projects have been done - and evaluated - governments seem unwilling to accept the results and spend the money, or (for instance) restrict car use.
When things do work - gradual infrastructure improvements (e.g. Copenhagen), mass cycle hire (Paris), comprehensive Safe Routes to School projects (Sustrans, various), there always seems to be concerns that it is 'value for money' or simply assertions 'but it wouldn't work in Edinburgh/UK/etc.
To get more people cycling (which all governments say they want to do) will cost cash, and some changes of attitude - and perhaps legislation.
"After decades of research, still no one knows if a smaller class, a new building, a simpler curriculum, a better-paid teacher or a bigger budget makes any difference."
http://www.guardian.co.uk/commentisfree/2010/may/27/michael-gove-free-schools-admissions-policy
(ALSO "An Edinburgh academic calculated that the academies were costing £5m for each "improved pupil", staggeringly bad value for money.")
The release of the Cycling Action Plan for Scotland is imminent. There are high hopes for the document. Will it have Scottish Government money attached?